1. Field of the Invention
This invention relates to a device for automatically measuring the refractory diopter of the eyes, and more particularly relates to an auto-refractometer to permit the automatic measuring of the refractory diopter of the eyes using invisible infrared rays as measuring rays and providing instantaneous indication of diopter in the form of digital data.
2. Description of the Prior Art
To optically measure eyes, there are two methods - one utilizing information provided by the person being tested and the other using external measuring devices.
In practising the first method, a device such as a vision tester has been widely applied for many years, but such a device provides no accurate measurement because of self-consciousness of the testee, and such a device also requires considerable floor space for measuring. Also, only a specialized optical engineer can measure the refractory diopter.
To practice the second method, considerable skill is necessary for measurement, and presently measuring accuracy is low because of an effect on the eyes of strong measuring rays projected thereon.